Universal Serial Bus (USB) connector is a serial bus standard of a connection between 3C device and a peripheral device and also a technique specification for an input/output interface. The USB connector is widely used in 3C device (for example an information communication device (such as a personal computer, a mobile device and so on), a camera device, a digital TV, a game machine and so on). Accordingly, the USB connector is divided into a USB receptacle connector and a USB plug connector. The USB receptacle connector is installed in the electronic devices described above and the USB plug connector is electrically connected to the connecting cable for information transmission. Therefore, the most signification advantage of the USB connector is hot-plugging and plug-and-play. Since USB 1.0 is released in 1996, the transmission speed thereof is 12 Mbit/s and USB 2.0 is improved to be 480 Mbit/s (Hi-speed). And now, USB 3.0 is 5 Mbit/s (super-speed) and the transmission speed is much faster and supported duplex transmission, fiber transmission and so on.
The design of the USB 3.0 is not to replace USB 2.0 and is to upgrade and assistant capability thereof. If the product includes a USB 2.0 interface, only USB 2.0 capability is required. Therefore, from a view of transmission interface technique, both are two different protocols. Accordingly, in order to downward compatibility, the hardware, software and connector for USB 2.0 and USB 3.0 are designed to be similar and USB 2.0 and USB 3.0 can be compatible to each other.
Please refer to FIG. 1A, it is a view illustrating a USB receptacle connector in prior art. As shown in FIG. 1A, a regular USB 3.0 receptacle connector includes a receptacle connector shell 901 and the shell 901 is surrounded by a receptacle connector tongue plate 902. A top surface of the receptacle connector tongue plate 902 includes four USB 2.0 receptacle connector terminals (VBUS, D+, D− and GND) able to compatible with USB 2.0. In addition, it also includes five USB 3.0 receptacle connector terminals 904 (SSRX+, SSRX−, GND_DRAIN, SSTX+, and SSTX−) able to connect to the USB 3.0 interface. The USB 3.0 receptacle connector terminals are disposed in a front end of the receptacle connector tongue plate 902 and the USB 2.0 receptacle connector terminals are disposed in a back end of the USB 3.0 receptacle connector terminals 904.
Thereafter, please refer to FIG. 1B, it is a view illustrating a USB plug connector in prior art. The USB 3.0 connector includes a USB 3.0 plug connector 90 and a USB 3.0 receptacle connector 92. As shown in FIG. 1B, the USB 3.0 plug connector 92 includes a plug connector shell 921 surrounded by a plug connector tongue plate 922. The top surface of the plug connector tongue plate 922 also includes four USB 2.0 plug connector terminals 923 (VBUS, D+, D− and GND) and five USB 3.0 plug connector terminal 924 (SSRX+, SSRX−, GND_DRAIN, SSTX+ and SSTX−). The different from the USB 3.0 plug connector 8 is that the USB 3.0 plug connector terminal 924 is disposed in a back end of the USB 2.0 plug connector terminal 923.
Now, please refer to FIG. 1C, it is a sectional view illustrating the connection between the USB receptacle connector and the USB plug connector in prior art. As shown in FIG. 1C, when the USB 3.0 plug connector 90 is connected to the USB 3.0 plug connector 92, the plug connector shell 92 is plugged into the receptacle connector shell 90 and a portion of the receptacle connector tongue plate 902 and the plug connector tongue plate 922 are overlapped without contacting to each other. The USB 2.0 receptacle connector terminal 903 is connected to the USB 2.0 plug connector terminal 923 and the USB 3.0 receptacle connector terminal 904 is connected and conducted to the USB 3.0 plug connector terminal 924 so as to transmit and receive signal.
Please refer to FIG. 1D, it is a top transparent view illustrating the conventional USB receptacle connector. The USB 2.0 receptacle connector terminals 903 in the conventional USB 3.0 receptacle connector are arranged in parallel and the USB 3.0 receptacle connector terminals 904 are also arranged in parallel on top and bottom respectively. The four USB 2.0 receptacle connector terminals 903 are arranged alternatively in the cavities between the five USB 3.0 receptacle connector terminals 904. In accordance to FIG. 1A and FIG. 1D, the four USB 2.0 receptacle connector terminals 903 and the five USB 3.0 receptacle terminals 904 are very close to each other, and it is easy to have crosstalk interference in D+/D−, SSTX+/SSTX− and SSRX+/SSRX− so as to affect the quality of the transmission. Similarly, the same problem is occurred in the USB 3.0 plug connector 92.